We want to subtract 8x + 3 from -2x+5. We can create an expression to represent this.
-2x + 5 - (8x + 3).
After this, lets distribute the - sign (think of this like expanding something with -1).
-2x + 5 - 8x - 3
Lastly, we just need to combine like terms.
-2x + 5 - 8x - 3
Combine the 5 and -3 to get 2.
-2x + 2 - 8x
Combine the -2x and -8x to get -10x.
-10x + 2
The final answer to the question is therefore A.